Pump



March 16, 1943. R. P. MILLER 2,313,836

' PUMP I I Filed July 15, 1939 3 Sheet s-Sheet 1 INV ENT OR.

Robe/i1 P Miller F24 Q 20 5 swim/3M1 v ATTORNEY.

the fluid under pressure Patented Mar. 16, 1943 UNITED. STATES PATENT OFFICE PUMP Robert P. Miller, San Gabriel, Calif. Application July 15, 1939, Serial No. 284,720

13 Claims.

This invention relates to pumping a fluid by fluid pressure; the fluid which is to be pumped being herein referred to as production fluid and which pumps-the production fluid being herein referred to as displacement fluid.

The invention is particularly applicable to petroleum wells in which the production fluid is from a production zone of the well and the displacement fluid is: any suitable gas supplied under pressure from any desired source. In practice, a production string may extend through usual well casing to the production zone of the well with displacement fluid supplied via the annular space at the exterior of the production string, or the production string may surround an inner conduit through which displacement fluid is supplied. I g

It is an object of the invention to shut off admission of displacement fluid to the lower end of the production string so that production fluid may rise in the production string, this being the filling period; and to then admit displacement fluid to the lower end of the production string for elevating the column of production fluid, this being the discharge period. More particularly it is an object of the invention to control alternate shut off and admission of displacement fluid by reciprocating an operating element from the earthfs surface, so that while the operating element is lowered admission of displacement fluid is shut off, and while the operating element is lifted displacement fluid is admitted.

By lifting the operating element to admit displacement fluid, the column of fluid which is elevated via the production string tends to maintain the operating element in its lifted position; whereas if lowering the operating element admitted displacement fluid, the column of fluid then elevated via the production string would tend to displace the operating element from its lowered operative position.

It is a further object of the invention to automatically control reciprocation of the operating element and to independently adjust the time intervals during which the operating element is elevated and lowered respectively, so as to provide any desiredv filling period during which admission of displacement fluid is shut oiT and any desired discharge period during which displacement fluid is admitted to the production string.

It is a still further object of the invention to adjustably tension the means which suspends the operating element, so that irrespective of stretch inherent in that particular suspension means which is being used, reciprocation of the suspension means permits positive shifting of the operating element to either lowered or elevated position, rather than merely alternately stretching and relieving tension in the suspension means without reciprocating the operating element.

It is a still further object of the invention to conveniently indicate the weight of the operating element which is carried by the suspension means, so that diiierence in indicated weight when the suspension means is raised and lowered will indicate whether the operating element is being reciprocated for controlling admission of displacement fluid or is remaining in its lowered position while reciprocation of the suspension means merely alternately'stretches and relieves tension in the suspension means. 7

It is a still further object of the invention to adjust the stroke of the suspension means so as to reciprocate the operating element between such lowered position as will shut 'off admission of displacement fluid'and such elevated position as will admit displacement fluid to the production string.

It is a still further object of the invention to control admission of displacement fluid at any desired level in the production string, with that portion of the production string which depends from the control means comprising conduits which communicate with one another at their lower ends, and the upper ends of which communicate respectively with the control means and with that portion of the production string which extends upwardly from the control means tothe earths surface;' and to arrange the control means so that lowering the operating element not only shuts oiT admission of displacement fluid to the depending conduit which communicates with the control means but also vents said conduit, and lifting the operating element not only admits displacement fluid to the depending conduit which communicates with the control means but also closes the vent in said conduit.

By this arrangement, when the operating element is lowered, production fluid rises in both conduits which depend from the control means, admission of displacement fluid being shut off and the vent for the depending conduit which communicates with the control means being open to permit escape of displacement fluid of a precedingdischarge period; and when the operating element is lifted, displacement fluid is supplied via the depending conduit which communicates with the control means, with the vent for said conduit closed. The displacement fluid thus flows downwardly through the depending conduit which communicates with the control means, displacing production fluid from said conduit and then elevating, via the depending conduit which communicates with the upper portion of the production string, that column of production fluid standing in said conduit and that column of production fluid which has been displaced from the first mentioned depending conduit. The displacement fluid then rises in the depending conduit which communicates with the upper portion of the production string, raising the column of production fluid which is in said conduit in advance of said displacement fluid and thereby elevating said production fluid through the upper portion of the production string for discharge at the earths surface.

By directing the displacement fluid downwardly through the depending conduit which communicates with the control means and thence upwardly through the depending conduit which communicates with the upper portion of the production string, the column of production fluid standing in both conduits is elevated during each discharge period, and the level at which the lower ends of the two depending conduits communicate may be at any desired level below the control means. If displacement fluid is supplied to the control means from the annular .space at the'exterior of the production string, the-control means may thus be above the production zone of the well, with a packer below the control means shutting ofi the annular supply space from the production zone, and the conduits which depend from the control means may extend to any desired level within said production zone. If the production string is a double- .string with displacement fluid supplied to the control means via the annular space between the two strings, the control means may be above the level at which the double-string ends, with the conduits which depend from the control means of a diameter adapting them for reception in the depending portion of the well bore which extends into the production zone and which may be ofreduced diameter below the doublestring.

By venting (during the filling period) that depending conduit'which communicates with the control means, the displacement fluid which re- ,mains in said depending conduit after admission-f displacement fluid has been shut off at the end of the preceding discharge period, escapes from said depending conduit so that production fluid is free "to rise in both the conduits which depend from the control means. The hydrostatic head of that volume .of production fluid which constitutes the slug which is to be elevated during the nextdischarge period, is thus materially lessthan if the same volume of production fluid entered only that depending conduit, which communicates with the upper portion of the production string. Back-pressure against'the formation such'as would retard production is thus appreciably reduced.

It'is a still further object of the invention to control the volume of production fluid which enters the production string at each filling period, irrespective of the time interval of said filling period. By this arrangement, the time .intervals of alternate filling and discharge may be adjustedfor maximum economy of operation,

while maintaining total production within a predetermined limit.

It is a still further object of the invention to adjust the volume of production fluid which enters the production string during each filling period, so that total production will be in accordance with proration for the particular well, irrespective of the particular timing which is employed.

Further objects of the invention will be readily understood from the following description of the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of the upper end of a well equipped for pumping in accordance with the present invention, showing the actuating and control mechanism for reciprocating an operating element in the well.

Fig. 2 is an axial section through the lower end of the well, showing the pumping mechanism and its operating element and also showing kick-over means.

Fig. 3 is a vertical section on the line 3-3 of Fi 1.

Fig. i is a transverse section on the line 4- 2 of Fig. 3.

Fig. 5 is a detail elevation of the control mechanism.

Fig. 6 is a transverse section on the line 6-6 of Fig. 5.

Fig. '7 is a detail axial section through'the pumping mechanism of Fig. 2.

Figs. 8 and 9 are transverse sections on the lines 8-43 and 9-9 respectively of Fig. '7.

Fig. 10 is a detail axial section through a modiflcation of the pumping mechanism.

Figs. 11 and 12 are transverse sections on the lines ll-H and l2-l2 respectively of Fig. 10,.

Fig. 13 is a detail axial section through a still further modification of the pumping mechanism.

Fig. 14 is a transverse section on the line 14-44 of Fig. 13.

Figs. 15 and 16 are axial sections on the lines -i5-i5 and i5!6 respectively of Fig. 14.

Fig. 17 is a transverse section on the line ll-ll of Fig. 15.

Fig. 18 is a transverse section on the line iii-l8 of Fig. 16.

By way of example, the invention is illustrated and described in connection with the pumping of petroleum wells, the pump being installed in a production string A which in the illustrated embodiment of the invention has an annular space B at the exterior of the production string through which gas under pressure .and constituting displacement fluid is supplied to a control means .0 which is mounted in the pro-duction string adjacent its lower end.

he control C is actuated by an oper element 1) which is suspended from a flexble line E; and at the earths surface the line is raised and lowered by actuating means F which has control mechanism G.

That portion of the production string which depends from the control means C preferably comprises a conduits H and I which are bly arranged one Within the other; and the displacement fluid which is admitted via the control means flows downwardly through one of said conduits, which at its lower end communicates with the second depending conduit, and then rises throug-h'said second depending conduit, which at its upper end communicates with that portion of the production string which extends upwardly from the control means to the earths surface.

The actuating means F which raises and lowers the line E is preferably operated by fluid pressure. For this purpose, a vertical cylinder I is positioned at the earths surface alongside the well, and a piston 2 is adapted for reciprocation in the cylinder and is connected to an up- Wardly projecting piston rod 3. A sheave 4 is journaled in a frame 5 which is connected to the rod 3, and the frame 5 has guide means 5 adapted for reciprocation in guideways 1 which project upwardly from the cylinder l. Fluid pressure is alternately supplied and exhausted from the lower end of the cylinder l for alternately raising and lowering the sheave 4; and adjustable stops 9-H) which are adapted for respective engagement by the upper end of the frame 5 and by the upper end of the cylinder l limit raising and lowering of the sheave 4.

The line E is raised and lowered by reciprocating the sheave 4. Means are preferably provided for adjusting the tension of the line E, i. e. for adjusting that portion of the weight of the operating element D which is supported by the control means C when said operating element is in lowered position; and means are preferably provided for indicating the weight suspended from the line E. For this purpose, the end l2 of the line E projects upwardly through the upper. end of the production string A, preferably via a stufling box l3, and is connected to a clamp M, with the line I2 then extending upwardly and over the sheave 4 and thence downwardly to a spool (not shown) on which the dead end of the line is wound. The clamp I4 is suspended from a cable l5 which also extends upwardly and over the sheave 4 and thence downwardly to the lever iii of a weight indicator l1. By adjusting the point at which the clamp l4 engages the line l2, any desired weight of the operating element D may be supported on the control means C when the line E is lowered, thereby suspending the remainder of the weight of the operating element from the line E so as to maintainany desired tension on the line when it is in its lowered position. The weight suspended from the line E is shown on the weight indicator ,I'l, so that difference in indicated weight when the line is lowered but still carries a portion of the weight of the operating element, and when the line is elevated so that it carries the entire weight of the operating element, indicates whether raising and lowering the line E is properly reciprocating the operating element D to alternately exert desired weight on the control means C and then lift said weight.

The fluid pressure which reciprocates the piston 2 is automatically controlled; and the control mechanism is adjustable, for adjusting the time interval during which fluid pressure is supplied for elevating the piston 2, and for independently adjusting the time interval during which fluid pressure is relieved to permit lowering of the piston.

For this purpose, the fluid pressure which is employed is preferably pressure of the displacement fluid which is utilized for pumping the well and which is supplied from any suitable source to the annular space at the exterior of the production string A. As shown at Fig. 1, the production string A is suspended in well casing 23, with the production string projecting above the well casing via a usual casing head 21. Displacement fluid is supplied to the annular space B between the production string A and the casing 23; via a suitable supply conduit 22. A conduit 23 closing the bleeder valve 36.

communicates with the casing head 2|, whereby a portion of the displacement fluid, after reduction in pressure, is utilized for reciprocating the piston 2. For this purpose, a pressure reducer 21 is connected to the conduit 23, and a supply conduit 24 leads from the pressure reducer to the lower end of the cylinder I. An exhaust conduit 25 leads from the conduit 24, preferably to that portion of the production string which projects above the casing head 2| and which is provided with a flow outlet 26.

The control mechanism G alternately admits fluid pressure. via conduit 24 to the cylinder l and exhausts said fluid pressure via the conduit 25; the control mechanism being automatically actuated and adapted for independent adjustment of the time intervals during which pressure fluid is supplied and exhausted respectively. For this purpose, diaphragm valves -3! may respectively control the supply and exhaust conduits 24-25, with fluid pressure which is supplied via conduits 32-33 adapted to respectively open the normally closed valve 30 and close the normally open valve 3|. Fluid pressure may be supplied to the conduits 32-33 via a conduit 34 which branches from the pressure reducer 2'! and which is preferably provided with a pressure regulator 35; and supply and exhaust or. pressure via the conduit 34 is automatically controlled.

For this purpose, a bleeder line 29 may extend from the conduit 34, and the bleeder line may be alternately opened and closed by a valve 36 which may be actuated by usual clock mechanism. For example, a clock mechanism 3'! may rotate a disc 33, and the valve 36 may be mounted on a lever 39 which is pivoted at 23 and which during rotation of the disc 38 is alternately spring retra cted to open the valve and rides on circumferentially spaced abutments on the disc to close the valve. The abutments are shown as rollers 40 mounted on clips 4| which are adapted for detachable mounting on the disc 38 in any desired circumferentially spaced relation. The speed of rotation of the disc 38 and the circumferential spacing of the rollers 40 is adjusted so that the lever 39 is spring retracted for opening the bleeder vlave 36 during successive time intervals of any desired duration, between successive engagements of the lever by the circumferentially spaced rollers.

Means are provided for adjusting the successive time intervals during which the lever 39 rides on the circumferentially spaced rollers for For this purpose a cam 42 on the lever 39 is adapted for engagement by the successive rollers til for swinging the lever to close the bleeder valve; and the cam is adjustable to vary the length of its surface which rides on a roller for maintaining the lever in valve-opening position. As an instance of this arrangement, the cam 42 may be adjustable in a slot at the end of the lever 39, preferably by a worm drive 43 which is manually rotated by a knob 44, so that the cam formsa contact surface 45 of adjustable length in the direction of movement of the rollers 49 which cooperate with the cam.

During rotation of the disc 38, the lever 39 is spring retracted between engagement of successive rollers with the cam, thereby opening the valve 36 so that pressure is built up in the conduit 34 and from the conduits 32-33, via the line 29. The valves 39-3l are thus spring actuated for. closing the valve 39 and opening the valve 31, whereby fluid pressure is exhausted from the cylinder .i to permit retraction of the piston 2 for lowering the line El so that the operating element -D actuates the control means for shutting off admission of displacement fluid, thereby determining the filling period by the time interval between engagement of successive rollers with the :cam. During engagement of successive rollers with the cam, the lever 39 closes the bleeder valve 36 so that perssure is built up in the conduit and in the conduits i s-33, thereby opening the 3t and closing the valve 35. Fluid pressure is thus supplied. to the cylinder I for elevating the piston 2 and thus raising the line E so as to lift the operating element D for admitting displacement fluid via the control means 56, thereby determining the discharge period by the time interval during which the cam is engaged by a roller.

The time interval for travel of the piston 2 to either its raised or lowered position may be adjusted by needle valves idl! in the conduits sir-'25 respectively; and the time interval during which the piston then remains in lowered position, i. e. the filling period, may be adjusted by adjusting the speed of the disc 38 and the spacing of the rollers 33; and the time interval during which the piston 2 remains in elevated position, i. e. the discharge period, may be adjusted independently of the filling period by adjusting the length of the contact surface 65 which is engaged by the successive rollers.

The control means C which is actuated by raising and lowering the operating element D may be arranged as shown at Fig, 2 and as shown in detail at Figs. '7 to 9. This construction is applicable where the production string A comprises a single string of tubing, with displacement iluid supplied via the annular space E. between the tubing string and the surrounding well casing in.

As an instance of this arrangement, the production string comprises a string of tubing 55, with an obstruction 553 suspended from this tubing string and forming the control means C, and with a continuation of the tubing string depending from the obstruction as shown at 52 and forming the depending conduit H which surrounds the depending conduit 1. The obstruction is axially bored from its upper end to form a cylinder 53 which terminates short of the lower end of the obstruction and communicates laterally with a bore which opens through the lower end of the obstruction. The upper end of the bore 5% communicates with the cylinder 53 via a transverse bore as which is in spaced relation above the lower end of the cylinder; and the transverse bores 56 provide communication between. the exterior of the production string and the cylinder 53, at a point spaced below the point of communication between the bore 55 and the cylinder. A piurality of bores 51 extend into the obstruction 55 from its upper end, and at their lower ends communicate with a common bore 58 which opens through the lower end of the obstruction Bil. A transverse bore 59 provides communication between the cylinder 53 and one of the bores 5'5, at substantially the level of the bore 55.

The conduit I communicates with one or the other of the bores i i-58, and is shown as a pipe st of appreciably smaller diameter than the tubing 52 and depending from the bore 53 to any desired level in said tubing; and at its lower asrlaeae end the pipe 66 is open to the bore of the tubin .52 to provide communication between the conduits H-I. The conduit H thus communicates with the control means C via the bore 54 while the conduit I communicates via the bores 51-58 with the upper portion of the production string A; although if desired the pipe 69 may depend from the bore 54, in which case the conduit H would communicate with the upper portion of the production string via the bores 51-58 while the conduit I would communicate with'the control means via the bore 54.

Below the level of communication between the conduits H-I a foot valve 6! is preferably provided in the tubing 52; and below this foot valve a fluid screen 62 depends from the tubing 52 for entrance .of production fluid from a production zone of the well and via a perforated section 63 of the well casing which surrounds the fluid screen. A packer t l is provided in the annular space B between the production string and the surrounding well casing, at a point below the bores 53 of the control means and above the perforated well casing 63. Displacement fluid supplied via this annular space is thus shut off from the production zone of the well, and is adapted for admission via the bores 56 of the control means 0. The control means 0 is positioned above the production zone, while the conduits H-I which depend from the control means may extend to any desired level within the production zone.

Reciprocation of the operating element D admits displacement fluid via the bores 5% to the cylinder 53 and thence to the bore 54 while shutting olf communication between the transverse bores 55-59; or shuts off communication between the bores 55 and the cylinder 53 while providing communication between the transverse bores 555L418 for venting the bore 54 via said transverse bores and thence via the communicating bore 51.

For this purpose, a piston valve 65 is adapted for reciprocation in the cylinder 53 and is suspended from a valve stem 56 which projects through a closure ill for the upper end of the cylinder. The valve stem has an abutment head 68 and a spring 69 tends to retract the valve to its upper limit of movement, which is its position when opening the bores 58 to the cylinder 53. A guide iii preferably surrounds the valve stem $3 for guiding the reciprocating operating element D into engagement with the head 68.

When the line E is lowered, the operating element D which is suspended therefrom, depresses the head 58 and projects the valve t5 against the tension of its spring 69, thereby shutting off admission of displacement fluid via the bores 56 and at the same time venting the bore 5%. This is the filling period, during which production fluid opens the foot valve ii! and rises in the conduits Bib-6d. Depending upon the formation pressure and the time interval before the line E is again elevated 'forretracting the valve 65 by its spring 59, the production iluid which rises in the conduit 86 may then rise in the bores 51 and may reach a level in the production string A above the control means C before the end of the filling period.

When the line E is again elevated, the operating element D is also raised so that th valve .65 is retracted by its spring 6%, thereby closing the vent at 55-59 and admitting displacement fluid via 56535 2'. This is the discharge period, during which pressure of the incomin displacement fluid is exerted via bores 5354 against the production fluid in the conduit 52, thereby closing the foot valve 61 and lowering the level of the production fluid which is trapped in the tubing 52 above the closed foot valve, for elevating production fluid via the pipe 69 and the bores 51 and thence via the tubing i i for discharge at the earths surface via the outlet 26.

When the line E is again lowered, displacement fluid which istrapped in the bore 54 and in the tubing 52 above the lower end of the pipe 60, is vented' via 55-59 and the production fluid again opens the foot valve 6| for admission of said production fluid to the conduits 52--6il for repeating the cycle of operation.

If desired, means may be provided whereby during the discharge period displacement fluid may be supplied at any desired pressure via the annular space B, with its rate of flow regulated during its passage via the bores 53-54 so that irrespective of the pressure of said fluid it will be supplied to the tubing 52 and thence to the pipe 60 at a rate of flow at which it will not blow through the slug of production fluid which is being elevated via the tubing 5| in advance of said displacement fluid.

For this purpose. the rate of flow of displacement fluid from the bore 54 into the tubing 52 may be regulated by suspending a pipe 13 of predetermined bore and length from the bore 54. Pipes 13 of different bore and length may be interchangeably employed by providing a threaded connection 14 between the bore 54 and the pipe 13; and the pipe 13 which is employed has a bore and length providing predetermined restriction to flow therethrough, This construction, i. e. employing the pipe 73, is particularly applicable where displacement fluid is supplied at relatively high pressure at the earths surface or is supplied from an upper pressure zone of the well which is being pumped.

In the case of high pressure supply at'the eart 's surface, the necessity of reducing pressure before admitting the displacement fluid to the annular space B is thus eliminated. The displacement fluid may be admitted to the space B at any high pressure at which it is furnished from the source of supply; and a pipe 13 is employed having a bore and length, which in accordance with pressure of the displacement fluid, restricts flow via said pipe so that the displacement fluid is discharged into the tubing 52 at a restricted rate of flow whereby it will elevate production fluid in advance of said displacement fluid and via.6'05851-5l without danger of blowing through the slug of production fluid.

In similar manner, when displacement fluid is supplied to the annular space B from an upper pressure zone of the well, the displacement fluid may be supplied via 5B53-54 at whatever pressure it comesfrom the pressure zone, a pipe I3 being employed, which in accordance with pressure of said displacement fluid, restricts flow via said pipe so that the displacement fluid is discharged into the tubing 52 at a restricted rate of flow which will eliminate possibility of the displacement fluid blowing through the slug of production fluid which it is elevating via the tubing 5|.

When the production string is a double-string of tubing, the displacement fluid may be supplied via the annular space between the tubing strings, with the control means C constructed as shown at Figs. to 12. Asan instance of this arrangement, a string of tubing 51a is surupper end so as 5 rounded by a second tubing string 15, with the tubing 5la forming the production string A, and with the annular space between the tubing strings Sta-45 forming the annular space B through which displacement fluid is supplied from a suitable source at the earth's surface.

The arrangement at the earths surface is not illustrated, being of usual construction comprising a casing head on well easing which surrounds the outer tubing string 15, with the tubing string 5m projecting above the casing head for discharge of production fluid, and with the annular space B which is between the tubing strings 5|a15, closed to the annular space between the outer tubing string and the surrounding well casing. Displacement fluid is supplied to the annular space B from any desired source, with a portion of the displacement fluid utilized for operating the actuating means'F as previously described; and the annular space between the outertubing string 15 and the surrounding well casing is arranged for discharge of gas from said annular space.

Guide means 16 may be provided between the tubing strings 5|a15; and an obstruction 50a which forms the control means C is suspended from the tubing 5m, with the tubing '15 fixed to the obstruction 50a in spaced relation below its to close the lower end of the annular space B. A tubing string 52a, which may be-of appreciably smaller diameter than the tubing 15, depends from the obstruction 50a and forms the depending conduit H which surrounds the depending conduit I,

The obstruction 50a is provided with bores arranged similarly to those formed in the obstruction 50 (previously described) and designated by the same reference numerals but with the exponent a, except that the bore 51a which communicates with the transverse bore 59a, is closed at its upper end as shown at 11 and its lower end instead of opening into the bore 58a communicates via lateral port 18 with the annular space at the exterior of the outer tubing string 15. The remainder of the bores 51a communicate at their lower ends with the bore 58a ,and open through the upper end of the obstruction 50a as previously described. The bores 56a communicate with the annular space B between the tubing strings 5la-I5.

A pipe 60a forms the conduit I .and depends from the bore 58a, with the pipe 60a (at its lower end which is not shown) communicating with the tubing string 52a, and with a check valve 19 in the upper end of the pipe for a purpose hereinafter described. Production fluid is admitted. to the tubing string 52a from a production zone of the well, via a foot valve (not shown), as previously described.

The depending conduits H-I may thus extend into a restricted lower portion of the well bore to any desired level within the production zone, with the double-tubing string Sid-15 terminating above this restricted portion of the well bore and with the control means C also positioned above this restricted portion of the well bore.

A piston valve 55a is adapted for reciprocation in the cylinder 53a for controlling the intake ports 55a and the vent ports 55a59a. The op eration is the same as that explained in connection with Fig. 7, except that during the filling period the vent via 55a59a discharges via that bore 51a which is closed at its upper end, and thence via port 78 into the annulartspace at the exterior of the double-tubing string, for diseh i m id nnular s ace at th ear hs surface.

The double-tubing string as thus described, provides for reduction of back pressure against the formation for insuring maximum production, particularly from wells of low static prese sure an'd'from wells which produce a large volume of gas. Gas from the production zone is free to rise in the annular space between the double-tubing string and the surrounding well r'iod, the check valve I9 is closed by pressure of the displacement fluid in the tubing string A above the control means C, and therefore only the displacement fluid which is trapped in 52a-.5,4'a and in the pipe 60a below the closedcheck valve, is vented via port'lSto the annular gas discharge space at the exterior of the double tubing string, withoutdisplacement fluid which, is'in the tubing. string A blowing-down via pipe 60a and upwardly via conduit 52a for venting via port 18 (as would be the case if the check, valve l9 were not employed). By thus venting only the displacement fluid trapped in 60a52a54a, pressure rapidly reduced at the, end, of the discharge period, to permit intake of production fluid for quickly inaugurating the nextfollowingfilling period;

'The, valve 65a isactiiate'd as previously described in connection with Fig. '7, i.' e. by ametnately loweringand raising the operating ele: ment D relative to. the head 68a which is provided on the'stem 66a of the valve, with spring 63a, yieldably' elevating the valvei'and wit'h guide means 10a insuring alinement of theoperatii'ig element with theheadof, the valve stem.

At Figs, 13 to 18 I have shown a modification whereby'the production fluid which enters dur ing the filling period, rises via'the conduit I and the control means 0 toonly, a predetermined level short of its static or working level, irrespective of the time interval before startingthe next, following discharge period. 'This prede termined level may be adjusted; and by thus adjusting the discharge at each discharge 138,- ri'od the well productionfor any desired period.

of time may be regulated to any desired total volume, while employing any desired time intervals between successive discharge periods.

As an instance of this arrangement, the construction is the same as that, shown at Figs. 1 and 2 except for detailsof the control means C, with corresponding parts indicated by the same, reference numerals but with the exponent b. An obstruction b which forms the control means C, is suspended from tubing string 5lb, with tubing 521) depending from the, obstruction 5% and forming the conduit H. Production fluid from the production zone of the well,

enters the conduit H Via a foot-valve (not shown), and a pipe 6% depends from the, ob,-

struction Silb within the tubing 52b and forms.

Piston valve 651) is adapted. for reciprocation,

in the cylinder 5312 which communicates with the bore 54b, and ports 5% communicate with the cylinder 5% and supply displacement fluid from the annular space B when the valve 651). has been spring retracted to its, upper limit of movement. The cylinder 53b audits communicating bore 541 are preferably laterallygoffset from the axis of the obstruction 5%, and at. the opposite side of the longitudinal axis of said obstruction a bore Bil extends into said obstruction from its upper end and terminates short of the lower end of said obstruction.

A balanced piston valve 8|,is adapted for reciprocation in the bore 83, and whenflin its lowered position it engages, cooperating valve seats 8283 Lateral ports B d-e85 communicate with the bore 88 above the valve seat 82 and below the valve seat 83 respectively, and, these ports open into a bore 85 which in turn opens through. the upper end of the obstruction Eilband intothe tubing MD. A port 81 communicates with the bore 80 between its valve seats 82-83, and opens into a bore 58] which in turn opens through the lower end of the obstruction 50b.

The pipe 601 depends from either of the bores closesthe bore of the production string at a level.

above admission of production fluid and, displacement fluid, i. e. production fluid is admitted to the production string via the lower end of the tubing 52b andthe pipe 6%, and displacement fiuid is admitted to; the production string via the pipefiflb, this pipe fiilbbeing a part ofthe production string; and the fluids rise thence via thebore 58b, whichis alsoa part of the production string, to the level of the valve 8l'.

A port 55b communicates with the cylinder 53b above the portsifib, andopensinto a bore 88: which in turn opens through; the lower end of the obstruction 5011; and a port 59b whi,ch is at approximately the same level as the port, 55b, provides communication; between the cylinder 53b and the bore 80, ata point; betweenthe valve seats 82 -83 Astem 66b for the valve 651), extends upwardly through a closure 61b for thecylinder 53b; and the balanced valve; 8} has a stern-9il which projects through a; closure; 9;I;for; the upper end of the bore. 80}; When the valvestem Bil-islowcred, a piston QZe-n said stem is receivedin, a dash-pot '93 whichis formed in the closure 9 I and which bleeds via restrictedoutlet 94to the tubing 5H). A head GBb-isprovided-on the valve stem 6617, with a spring. 6917. surrounding the valve stemand tendingto retract the valve b1 to its uppperlimit of movement; and zthe headSBb; is

valve- 652) so as toopen the;p o rt 55b totheport 59b and also. projects the; balanced valve- 81 1 against the retarding action f its dash-pot93- so as to engage the valve 8| with its seats 82-83 after a time interval determined by the retarding action of the dash-pot.

When the line E and the operating element D are lowered, admission of displacement fluid via the ports 55b is thus shut-off, thereby terminat-' ing the discharge period and inaugurating the filling period, and displacement'fluid which remains in 52b and in 6022 from the discharge period which has thus been terminated, is discharged into the bore 80 via 88-55b-59b and via Ssh-81. Consequently this displacement fluid is vented from the bore 80 via 84 and 85 and thence via 88 and the tubing |b as the balanced valve 8|, retarded by its dash-pot, moves toward closed position; and when the valve 8| finally closes its shut-off the vent for displacement fluid via 84 and 85.

As long as the upper portion of the tubing 52b and the pipe 601) are vented, production fluid may enter the tubing 52b and the pipe 80b, seeking its static or working level. This is the filling period. But instead of this filling period continuing until the rising production fluid reaches its static or working level or until the line E is again elevated for inauguratin the next following discharge period (as in the structure disclosed at Figs. 7 and 13), closing the vent via 84 and 85, after a, time interval determined by the retarding action of the dash-pot 93, builds up pressure in the upper portion of the tubing 52b and in the pipe 80?), thereby arresting intake of production fluid short of its static or working level. Therefore, irrespective of the time interval before the line E is again elevated to initiate the next discharge period, only a predetermined Volume of production fluid, determined by the retarded closing of the valve 8|, will have been trapped above the foot valve (not shown) which is mounted in the tubing 52b below the lower open end of the pipe 60b.

When the line E and the operating element D are then elevated (after any desired time interval) to start the next following discharge period, the valve 651) is retracted by its spring 69?) to first close the vent 55b 59b and then admit displacement fluid via the ports 53b; and the valve 8| is also elevated through its connection 95, which delays elevation of the valve until the vent 55b-59b has been closed,with said elevation of the valve 8| raising it from its valve seats 82-03. The displacement fluid which is admitted via the bores 561) thus exerts downward pressure in the tubing 5%, for elevating the predetermined trapped volume of production fluid via 60b- 58b8'|80 and thence via 84 and 85 and thence via 86 and the tubing 5| b, for discharge at the earths surface. This is the discharge period.

The volume of production fluid which is elevated during each cycle of operation, is thus determined by the rate of admission of fluid from the production zone with relation to the time interval (as determined by the dash-pot 93) between the start of each filling period and the closing of the valve 8|; and this relationship may be adjusted for admitting any desired volume of production fluid, by regulating the retarding action of the dash-pot 93. Such regulation is obtained by adjusting the weight of the operating element D which is exerted upon the head 68b when the line E is lowered. This adjustment may be made by interchanging elements D of diiferent weight so as to employ an element of desired weight, and/or by adjusting the point of clamping engagement between the upper end l2 of the line E and the cable |5 so that any desired weight of the element D is exerted against the head 681) when the line E is lowered, and/or by adjusting the stops 8-|0 for limiting reciprocation of the sheave 4 and consequent movement of the line E. In practice the desired adjustment is preferably obtained by selecting an operating element D of predetermined weight. As previously described the weight exerted against the head of the control mechanism is indicated at IT, and thus indicates when the weight exerted against the head 881) has been so adjusted as to provide desired regulation of the retarding action oi the dash-pot 93.

The various forms of the invention thus far described provide means whereby lowering. and raising the line E controls filling and discharge periods for respectively admitting production fluid and for elevating and discharging production fluid at the earths surface, with the line E automatically reciprocated and adapted for independent adjustment of the time intervals during which it is lowered and raised respectively, and with the construction whichis shown at Figs. 13 to 18 providing for controlling the volume of production fluid which is admitted during each filling period, irrespective of the time interval before starting the next following discharge period.

During elevation of the line E, its suspended operating element D may be elevated clear of the cooperating heads 68, 68a or 681), whereby the valve of the control means 0 is retracted solely by the action of its spring, this construction being shown at Figs. '2, l0 and 13; or if desired, and to prevent the possibility of the valve sticking in its projected position so that its cooperating spring is ineffective to retract it for starting the next discharge period, the operating element D may be positively connected to the cooperating head 68, 68a or 681). Lowering and raising the line E thus positively actuates the valve of the control means C, both for projecting and retracting the valve; but this positive connection is so arranged that when desired it may be readily released for withdrawing the line E and its operating element D without disturbing the control means C.

Such a, positive connection is shown at Fig. '7, employed in connection with the head 68, it being understood that the same positive connection may be similarly employed with the head 68a or 68b of Figs. 10 or 13.

As an instance of this arrangement, the head 08 is provided with a wedge projection 00 having undercut shoulders NH, and the lower end of the operating element D is provided with longitudinally projecting spring jaws I02 having abutments I03. ,When the operating element D is first lowered, the wedge I00 spreads the jaws I02 so that the abutments |03 engage beneath the undercut shoulders IN; and during normal reciprocation of the operating element D, the engagement 0|-| 03 positively reciprocates the head 68 with the reciprocating operating element. When it is desired to withdraw the operating element D, an abnormal strain is exerted via the line E, thereby spreading the jaws I02 so that their abutments I03 clear the shoulders I0 I, thus releasing the positive connection between the operating element and the cooperating head. To permit this spreading of the jaws, the undercut shoulders |0| and the cooperating surfaces of the abutments I03 are preferably slightly tapered.

If desired, the line E which extends into the production string of the well, may be employed, (in addition to its function of reciprocating the operating element D) for suspending any desired apparatus in the production string. For example, and as shown at Fig. 1f), the operating element D may be made in sections H35Hi6 having threaded couplings It! whereby apparatus such as-a pressure recorder I08, provided at its ends with similar couplings, may be detachably mounted between the sections l05-I 8%.

I claim:

1. In combination, a well string for production fluid having an annular space for displacement fluid surrounding the well string, the lower end of the well string communicating with a production zone of the well for admitting production fluid to the well string, a packer at the lower end of the annular space, a passageway between the annular space and the lower portion of the well string, a by-pass between the upper portion of the passageway and the well string, and a valve shitable to position opening the annular space to-the passageway and closing the by-pass', or shiitable to position closing the annular space to the passageway and opening the by-pass.

2. In combination, a Well string for production fluid and a second well string for displacement fluid surrounding one another in a well bore with an annular space surrounding the outer well string and communicating at its lower end with a production zone of the well, thelower end of the first well string communicating with saidproduction zone for admitting production fluid to the first well string, an obstruction in the first well string having a bore closed at one end and open at its opposite end for communication with the lower portion of the first well string, the obstruction having a port in the wall of the bore communicating with the bore of the second well string, the obstruction having a by-pass communicating with the bore between the port and the open end of the bore, the obstruction having second ports in the wall of the bore communicating respectively with the by-pass and the annular space, anda piston valve adapted for reciprocation in the bore, for closing the first port and shifting the piston valve clear of the second ports for com- L munication therebetween when the piston valve is moved in one direction, and for closing the second ports and shifting the piston valve clear of the first port for communication between the bore of the second well string and the lower portion of the first well string when thepiston valve is moved in the opposite direction.

3. In combination, a well string, means in the well controlling alternate admission of production fluid and displacement fluid to the well string for pumping production fluid via the well'string during admission of displacement fluid, operating means adapted for reciprocation in the well for controlling operation of the control means. by

alternately exerting and relieving. weight of. the" operating means on the control means, the con trol means including means operable by weight of the operating means exerted on the control means for terminating admission of production fluid at a time interval after inaugurating admission thereof and before subsequently admitting. dis-- placement fluid, means for'varying said time interval by adjusting weight of the operating means exerted on the control means, and means for adjusting weight of the operating means exerted on the control means.

4. In combination, a well string, means'in the well controllingalternate admission of production fluid and displacement fluid to the well string.

for pumping production' fluid via the well string during admission of displacement fluid, operating means adapted for reciprocation in the well for controlling operation of the control means by alternately exerting and relieving weight of the operating means on the control means, the control-means'includingmeans operable by weight of the operating'me'ans exerted on the control means for terminating admission of production fluid at a time interval after inaugurating admission thereof and before subsequently admitting displacement fluid, means for varying said time interval by adjusting weight of the operating means exerted on the control means, and means for indicating weight of the operating means exerted on the control means.

5. In combination, a well string, means inthe well controlling alternate admission of production fluid and displacement fluid to the well string for pumping production fluid via the well string during admission of displacement fluid, operating means adapted for reciprocation in the well for controlling operation of the control means by alternately exerting and relieving weight of the operating means on the control means, the control means including means operable by weight of the operating means exerted on the control means for terminating admission ofproduction fluid at a time interval after inaugurating admission thereof and before subsequently admitting displacement fluid, means for varying said time interval by adjusting weight of the operating means exerted on the control means, means for adjusting weight of the operating means exerted on the control means, and means for indicating weight of the operating means exerted on the control means;

6. In combination, a well string, means in the well for pumping production fluid via the well string, means in the well for controlling the pumping means, operating means adapted for reciprocation in the well for controlling operation of the control means by alternately exerting and relieving weight of the operating means on the control means, means for suspending and reciprocating the operating means in the well, and means for adjusting the suspension means for adjusting weight of the operatingmeans exerted on the control means.

'7. In combination, a well string, means in the well for pumping production fluid via the well string, means in the well for controlling the pumping means, operating means adapted for reciprocation in the well for controlling operation of the control means by alternately exerting and relieving weight of the operating meanson the control means, means for suspending and reciprocating the operating means in the well, and means cooperating with the suspension meansfor indicating weight carried by the suspension means.

8. In combination, an oil well, means in the well for producing the well, a weight, flexible means for suspending the weight in the well for cooperation with the producing means for controlling operation of the producing means, and means for indicating the amount of the Weight carriedb'y the suspension means.

9. In combination, a well'string adapted for alternate admission of production fluid and displacement fluid adjacent the lower end of the well string for pumping production fluid via the well string by the displacement fluid, a first valve adjacent the lower end of the well string controlling admission of displacement fluid, a second valve opening and closing the bore of the well string at-a level above admission ofsaid fluids;

and operating means controlling the valves, so that while the first valve is open and for a time interval after closing the same the second valve is open, and throughout the remainder of the time interval during which the first valve is closed the second valve is closed.

10. In combination, awell string adapted for alternate admission of production fluid and displacement fluid adjacent th lower end of the well string for pumping production fluid via the well string by the displacement fluid, a first valve adjacent the lower end of the well string controlling admission of displacement fluid, a second valve opening and closing the bore of the Well string at a level above admission of said fluids, and operating means controlling the valves, so

that while the first valve is open and for a time interval after closing the same the second valve is open, and throughout the remainder of the time interval during which the first valve is closed the second valve is closed, said operating means including means for adjusting the time interval after closing the first valve during which the second valve is open.

11. In combination, a well string adapted for alternate admission of production fluid and displacement fluid adjacent the lower end of the well string for pumping production fluid via the well string by the displacement fluid, a first valve adjacent the lower end of the well string controlling admission of displacement fluid, a second valve opening and closing the bore of the well string at a level above admission of said fluids, and operating means independently controlling the time intervals during which the first valve is open and closed respectively, said operating means controlling the second valve, so that while the first valve is open and for a time interval after closing the same the second valve is open, and throughout the remainder of the time interval during which the first valve is close-d the second valve is closed.

12. In combination. a well string adapted for alternate admission of production fluid and displacement fiuid adjacent the lower end of the well string for pumping production fluid via the well string by the displacement fluid, a first valve adjacent the lower end of the well string controlling admission of displacement fluid, a second valve opening and closing the bore of the well string at a level above admission of said fluids, andoperating means independently controlling the time intervals during which the first valve is open and closed respectively, said operating means controlling the second valve, so that while the first valve is open and for a time interval after closing the same the second valve is open, and throughout the remainder of the time interval during which the first valve is closed the second valve is closed, and said operating means including means for adjusting the time interval after closing the first valve during which the second valve is open.

13. In combination, a well string for production fluid and a space for displacement fluid surrounding one another, the lower end of the well string communicating with a production zone of the well for admitting production fluid to the well string, a passageway between the displacement fluid space and the lower portion of the well string, a by-pass between the lower and upper portions of th well string, a first valve shiftable to open position for opening the displacement fluid space to the passageway and closing the by-pass, or shiftable to closed position for closing the displacement fluid space to the passageway and opening the by-pass, a second valve opening and closing the bore of the well string between the upper end of the well string and the level at which the by-pass communicates with the upper portion of the well string, and operating means controlling the valves, so that while the first valve is shifted to open position and for a time interval after shifting the same to closed position the second valve isopen, and throughout the remainder of the time interval during which the first valve is shifted to closed position the second valve is closed.

ROBERT P, MILLER. 

